What was the primary cause of conflict between steppe nomads and settled communities

Steppe nomads would invade the settled communities to take control of pasture lands. Settled communities were in the fear of new or next invasion. The nomad's trade was not related to the gain but related to the goods provided themselves that they don't have that time Nomads were from two different cultures and districts.

Nomads speak a Turkic language. There were many nomads group who traveled on the silk road.  

answer; inductive techniques;